Steel columns & posts · Cardiff
Steel columns & posts in Cardiff
Calculations, approvals, propping, steel and making good for steel columns & posts across Cardiff.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Cardiff and nearby
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
About our steel columns & posts service in Cardiff
A steel column is an upright structural element that collects the load from a beam, floor or roof and carries it down to a foundation. In homes it is usually a square or circular hollow section or a universal column, welded to a base plate fixed to a concrete pad, and sized by a structural engineer for the load it carries.
Homes across Cardiff range from Victorian terraces to post-war semis and newer estates, and steel columns & posts look different in each. We cover the whole area, from the centre out to the suburbs. We plan the steel, the temporary support and the approvals around the building, then fix the price in writing once the scope is agreed.
What to expect
- The base plate is welded to the foot of the column and fixed to the pad with holding-down bolts. A cap plate at the top bolts to the beam above, so the two act together and the beam cannot slide off its support.
- A column delivers its load to the ground through a small area, so it normally stands on a concrete pad foundation rather than straight onto a floor slab. The pad spreads the load into firm ground at a depth set by the engineer.
- While the existing support is removed or the new column goes in, props hold the beam and the structure above. They are only taken out once the column is fixed, packed tight at the head and grouted at the base.
- Steel at floor level can corrode if it sits in damp. The detail at the base is designed to keep damp away, using grout, protective paint and the floor's damp-proof membrane, and a column in a cellar or garage may need a heavier coating.
- Adding a structural column is building work that building control needs to approve, with the pad usually inspected before concrete and the column before it is covered. The completion certificate at the end is the record to keep for any future sale.
How the job runs in Cardiff
Look and measure
We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.
Design and price
Calculations come back from the engineer and we confirm your fixed written price, line by line.
Building control
We submit the application or notice to Cardiff Council under the Building Regulations as they apply in Wales, before work starts.
Fit, inspect, finish
The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.
What do steel columns & posts cost in Cardiff?
As a guide, budget £460–£1,360 per column including VAT for steel column or post in Cardiff, based on published UK cost guides adjusted for prices in Wales (-9%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Steel column or post | £460–£1,360 per column | Column supplied and fitted with base and cap plates on a pad foundation |
| Basement or cellar steelwork | £2,300–£5,900 | Beams and columns with pad foundations under the floor above (excavation and waterproofing extra) |
| Fire protection to a steel beam | £140–£550 per beam | Fire-rated board boxing or an intumescent coating system as specified |
| Structural calculations for a beam | £230–£680 | Site measure or photos, beam and padstone design and calculations for building control |
Figures include our approximate regional adjustment for prices in Wales (-9%) and are rounded. How these figures are worked out.
Building control and neighbours in Cardiff
In Wales, structural alterations come under the Building Regulations 2010 as they apply in Wales. Cardiff Council handles building control for Cardiff. For work started or approved from 1 July 2026, the Welsh system uses an application to building control, dutyholders appointed in writing, a commencement notice before work starts and a compliance statement at the end.
The Party Wall etc. Act 1996 applies in Wales as well as England, so a beam bearing into a shared wall needs a party structure notice at least two months before work starts. We arrange notices through a party wall surveyor.
More in Cardiff
Local questions answered
What happens at the survey visit in Cardiff?
We look at the wall, the floor and ceiling either side and what sits above, measure the opening you want, and note cables, pipes and access for the steel. It usually takes under an hour and there is no charge.
Can I stay at home while the work is done in Cardiff?
Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.
How long does it take to fit a steel post?
The column itself can often be fixed in a day, but the whole job usually spans a few working days. The floor is cut and the pad dug, building control inspects it, the concrete is poured and left to cure, and then the column goes in and is packed tight to the beam.
Can a steel post replace a supporting wall?
Yes, in many layouts a wall can come out with a beam above it and one or more posts taking the beam's load down to the ground. This keeps most of the openness while shortening the span. The engineer decides how many posts are needed and where they can go.
Can a steel column be left exposed?
Yes, many people leave a column on show, painted to suit the room. In homes exposed steel commonly needs fire protection, often intumescent paint applied to the specified thickness as part of a compatible paint system. Building control checks the protection meets what was specified. Boxing in with fire-rated plasterboard is the alternative where a hidden column is preferred.
Can you replace an old timber or cast iron post?
Usually, yes. Old posts in cellars, garages and converted shops are often undersized, rotten or of unknown strength. The engineer assesses the load they carry and specifies a new steel column and pad. The structure is propped while the old post comes out, and the new column is packed tight before the props are removed.